A control device that executes a program to control a device to be controlled has conventionally been used. An example of such program is a sequential function chart program containing information on steps and transitions. A sequential function chart program is hereinafter referred to as “SEC program.” An example of the control device is a programmable logic controller. A programmable logic controller is hereinafter referred to as “PLC.” A PLC has been suggested that stores, in a storage table, step information relating to the step currently being executed among the information contained in an SFC program, and displays the step information on a display device to notify the step currently being executed in the SEC program (see, e.g., Patent Literature 1).